1. Field of the Invention
The present invention relates to a multi-layer hose suitable as a fuel hose for vehicles, and particularly, to a multi-layer hose excellent in anti-fuel-permeability to alcohol blended fuels and excellent in interlayer adhesion property.
2. Description of the Related Art
In recent years, regulations to hydrocarbon transpiration gases from vehicular fuels have been highly tightened, particularly in and around the U.S.A. Addressing such regulation, there are advancing developments of rubber hoses for fuels.
In particular, there are proposals of multi-layer hoses including an intermediate layer having a resin material provided as a fuel-proof barrier, and inner and outer layers having rubber materials laminated on both sides of the intermediate layer, to have a secured connection-pipe sealing property, anti-fuel-permeability, flexibility, etc.
There is a multi-layer hose proposed in Japanese National-Phase Patent Application Laid-Open Publication No. 2004-506548, which has a fluorine-contained rubber (FKM) or acrylonitrilebutadiene rubber (NBR) disposed as an inner layer, a ternary copolymer THV (tetrachloroethylene-hexafluoropropylene-vinylidenefluoride) with a fuel barrier function disposed as an intermediate layer, and epichlorohydrin rubber (ECO) or nitrile rubber (acrylonitrilebutadiene rubber, NBR) disposed as an outer layer. Further, there is a proposal of a multi-layer hose having a layer of chlorosulfonated polyethylene rubber (CSM) or chrolinated polyethylene rubber (CPE) laminated on an outer layer.